Exhaust gas converter body structure

ABSTRACT

An exhaust gas converter body structure includes a main body, an inlet structure, and an outlet structure. The main body is configured to receive an exhaust gas converter between the inlet structure and the outlet structure. The inlet structure and the main body have complementary coupling geometries at a first joint. The outlet structure and the main body have complementary coupling geometries at a second joint. The coupling geometries of each of the inlet structure and the main body are at the first joint asymmetric or reflection-symmetric with respect to exactly one plane of symmetry and/or the coupling geometries of each of the outlet structure and the main body are at the second joint asymmetric or reflection-symmetric with respect to exactly one plane of symmetry. The configuration establishes a given angular position between the inlet structure and the main body and/or between the outlet structure and the main body.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119 of Application 10 2019 104 940.7, filed Feb. 27, 2019, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention concerns a body structure for an exhaust gas converter (hereinafter referred to as “exhaust gas converter body structure”).

TECHNICAL BACKGROUND

Exhaust gas converters are used to convert harmful components present in the exhaust gas of vehicles powered by internal combustion engines into less harmful or harmless components. Typical exhaust gas converters are exhaust-gas catalytic converters such as a three-way catalytic converter that converts carbon monoxide (CO), nitrogen oxide (NOx) and unburned hydrocarbons (HC) to carbon dioxide (CO₂), nitrogen (N₂) and water (H₂O), a NOx adsorber, a DeNOx catalytic converter or a SCR (Selective Catalytic Reaction) catalytic converter. As used herein, the term exhaust-gas converter also includes particulate filters.

An exhaust-gas converter is usually a substrate that has exhaust gas ducts extending through it and is disposed in a body structure. The body structure usually has a main body in which the substrate is disposed.

Often, a cushion mat is provided between the substrate and the main body. The cushion mat surrounds the substrate at least in sections, thereby filling a gap present between the main body and the substrate. In this way, the cushion mat determines the position of the substrate inside the main body.

Furthermore, the body structure usually comprises an exhaust gas inlet structure, and an exhaust gas outlet structure with the main body arranged in-between. The geometries of the inlet structure and the outlet structure are usually chosen such that an exhaust gas flow is distributed across the internal sectional area of the main body as uniformly as possible so that the exhaust gas flows through the substrate uniformly. The inlet structure and the outlet structure often have a fitting for an exhaust pipe at their ends facing away from the main body.

To facilitate a placement of the substrate inside the main body of the body structure, the inlet structure and/or the outlet structure are usually not coupled to the main body before the substrate has been placed inside.

Alternatively, the inlet structure and/or the outlet structure may be formed integrally with the main body, for instance formed from the main body by shaping sections of the main body.

The process of placing the substrate into the body structure is also referred to as “canning” Canning aims to achieve a reliable positioning of the substrate inside the body structure thereby avoiding any damage to the substrate.

Due to the increasingly restricted space conditions at the underbody of vehicles powered by internal combustion engines, it is often no longer possible to ensure the exhaust gas flow being distributed uniformly across the internal sectional area of the main body by means of the geometry of the inlet structure and the outlet structure only. Further, there is the general problem involved with a body structure for exhaust gas converters that inside the body structure corrosive condensate may form from the exhaust gas, thereby putting the body structure at risk of corrosion.

SUMMARY

Based on the foregoing, it is an object to avoid the above detriments and to provide a body structure for exhaust gas converters that enables a uniform distribution of the exhaust gas flow across the internal sectional area and reduces the risk of corrosion, while requiring little installation space.

Embodiments of an exhaust gas converter body structure comprise a main body, an inlet structure and an outlet structure. The main body is configured to receive an exhaust gas converter and arranged between the inlet structure and the outlet structure. The inlet structure and the main body engage at a first joint. In this context, “engage” means that the inlet structure and the main body abut on each other and/or are slotted together at the first joint. To this end, the inlet structure and the main body have matching, namely complementary, coupling geometries at the first joint. In this context, “matching coupling geometries” means that the coupling geometries allow the inlet structure and the main body to butt against each other more or less seamlessly. At a second joint, also the outlet structure and the main body engage, to which end the outlet structure and the main body have matching coupling geometries at the second joint. Similarly, “engage” means in this context that the outlet structure and the main body abut on each other and/or are slotted together at the second joint, while “matching coupling geometries” means that the coupling geometries allow the outlet structure and the main body to butt against each other more or less seamlessly. The coupling geometries of the inlet structure and the main body at the first joint are in themselves either asymmetric or reflection-symmetric with respect to exactly one single plane of symmetry. Alternatively or additionally, the coupling geometries of the outlet structure and the main body at the second joint are in themselves either asymmetric or reflection-symmetric with respect to exactly one single plane of symmetry.

According to an embodiment, a coupling geometry is “asymmetric” if it has no symmetry from a geometric point of view. According to an alternative embodiment, the feature “asymmetric or reflection-symmetric with respect to exactly one single plane of symmetry” is sufficiently met, when the coupling geometries are chosen such that a more or less seamless coupling of the inlet structure with the main body or the outlet structure with the main body is only possible at a single angular position and/or the inlet structure can more or less seamlessly only be fitted to a selected end of the main body and the outlet structure can more or less seamlessly only be fitted to the other end of the main body.

In this context, “more or less seamlessly” means that a residual gap can permanently be sealed gas-tight by conventional means (e.g., welding, soldering, crimping or gluing).

Particularly with an exhaust gas converter body structure, considerable advantages may be achieved when a coupling between the main body and the inlet structure and/or outlet structure is only feasible at a defined angular position.

A defined angular position ensures, for example, a reproducible distribution and streaming of the exhaust gas flow across the internal cross-section of the main body. This is important insofar as the inlet structure and/or outlet structure often have no rotational symmetry.

Further, a defined angular position ensures that the positioning of an exhaust gas converter body structure mounted at the underbody of a vehicle prevents any accumulation of corrosive condensate or reducing agent in areas particularly prone to corrosion (such as weld seams oriented in the longitudinal direction of the main body). This also allows the stability of the exhaust gas converter body structure, as well as its behavior in the event of an accident to be optimized and made reproducible.

Finally, a defined angular position also permits a fixed angular relationship between the inlet structure and/or outlet structure and an exhaust gas converter received in the main body and/or a cushion mat surrounding the exhaust gas converter. Thus, an overlap between a butt joint of the cushion mat and a weld seam oriented in the longitudinal direction of the main body may be prevented. A sophisticated capturing of the weld seam oriented in the longitudinal direction of the main body with a camera system, as commonly used, may then be omitted.

The inlet structure being only mountable to a selected end of the main body, and the outlet structure being only mountable to the other end of the main body further guarantees that the exhaust gas supplied through the inlet structure passes the exhaust gas converter received in the main body in the correct flow direction.

According to an embodiment, the coupling geometry of the inlet structure at the first joint and/or the coupling geometry of the outlet structure at the second joint comprises at least one protrusion extending towards the main body, or a recess extending away from the main body and/or at least one groove extending away from the main body and/or at least one protrusion extending towards the outside of the exhaust gas converter body structure, or a recess extending towards the inside of the exhaust gas converter body structure and/or at least one opening.

According to an embodiment, the coupling geometry of the main body at the first joint comprises at least one protrusion extending towards the inlet structure, or a recess extending away from the inlet structure and/or at least one groove extending away from the inlet structure. According to an embodiment, the coupling geometry of the main body at the second joint comprises at least one protrusion extending towards the outlet structure, or a recess extending away from the outlet structure and/or at least one groove extending away from the outlet structure. According to an embodiment, the coupling geometry of the main body at the first and/or second joint comprises at least one protrusion extending towards the outside of the exhaust gas converter body structure and/or a recess extending towards the inside of the exhaust gas converter body structure and/or at least one opening.

Thus, the desired asymmetry of the coupling geometries can be provided in a cost-effective manner. This also allows for the provision of different coupling geometries in such a number that only certain inlet structures can be coupled with certain main bodies and/or only certain outlet structures can be coupled with certain main bodies and/or can be coupled observing given angle relations.

According to an embodiment, the coupling geometry of the inlet structure at the first joint comprises at least one protrusion extending towards the outside of the exhaust gas converter body structure, while the coupling geometry of the main body at the first joint comprises at least one groove extending away from the inlet structure. According to an embodiment, the coupling geometry of the outlet structure at the second joint comprises at least one protrusion extending towards the outside of the exhaust gas converter body structure, while the coupling geometry of the main body at the second joint comprises at least one groove extending away from the outlet structure. Thus, the inlet structure and/or the outlet structure and the main body may match each other in a way that allows the inlet structure, respectively the outlet structure, to be slid into the main body at the region of the first, respectively second joint, with the protrusion of the inlet structure, respectively outlet structure, being disposed inside the groove of the main body, whereby, failing this, the main body may neither be slid into the inlet structure nor the outlet structure.

According to an embodiment, the coupling geometry of the inlet structure at the first joint has at least one groove extending away from the main body and the coupling geometry of the main body at the first joint has at least one protrusion extending towards the outside of the exhaust gas converter body structure. According to an embodiment, the coupling geometry of the outlet structure at the second joint has at least one groove extending away from the main body and the coupling geometry of the main body at the second joint has at least one protrusion extending towards the outside of the exhaust gas converter body structure. Thus, the inlet structure and/or the outlet structure and main body may match each other in way that allows the main body to be slid into the inlet structure, respectively outlet structure, at the region of the first, respectively second joint, with the protrusion of the main body being disposed inside the groove of the inlet structure, respectively outlet structure, whereby failing this, the main body may neither be slid into the inlet structure nor the outlet structure.

The groove may, for instance, also be a long hole that is open at one end and penetrates a wall of the inlet structure, the outlet structure or the main body completely.

According to an embodiment, the main body is, except for its coupling geometries, reflection-symmetric or rotation-symmetric. According to an embodiment, the sectional area of the main body is at a distance from its coupling geometries point-symmetric or axis-symmetric or circular or oval. With a respectively shaped main body, coupling the main body to the inlet structure or the outlet structure, respectively, with a defined angular position in a conventional manner is particularly difficult.

According to an embodiment, the inlet structure and/or outlet structure have also outside the coupling geometry no rotational symmetry and/or the inlet structure and/or outlet structure have an asymmetric sectional area at a distance from their coupling geometry. With a respectively shaped inlet structure and/or outlet structure, a coupling with the main body observing given angle relations has particular benefits. However, it is alternatively also possible that the inlet structure and/or the outlet structure are, outside of the coupling geometry, symmetric, and particular rotation-symmetric.

According to an embodiment, the exhaust gas converter body structure further comprises a first and/or second exhaust pipe. In this case, the first exhaust pipe engages with the inlet structure at a third joint, to which end the inlet structure and the first exhaust pipe have matching coupling geometries at the third joint. Alternatively or additionally, the second exhaust pipe engages with the outlet structure at a fourth joint, to which end the outlet structure and the second exhaust pipe have matching coupling geometries at the fourth joint. The coupling geometries of the inlet structure and the first exhaust pipe at the third joint are each either asymmetric or reflection-symmetric with respect to exactly one single axis of symmetry. In addition or alternatively, the coupling geometries of the outlet structure and the second exhaust pipe at the fourth joint are each either asymmetric or reflection-symmetric with respect to exactly one single axis of symmetry.

In this way, a predetermined angular relationship between the exhaust gas converter body and the first and second exhaust pipes can be ensured when mounting the exhaust gas converter body on the underbody of a vehicle. The desired asymmetry of the coupling geometries can be provided analogously to the above.

According to an embodiment, the first and/or second exhaust pipe are, with the exception of the coupling geometries, reflection-symmetric or rotation-symmetric or the first and/or second exhaust pipe have a circular or oval sectional area.

According to an embodiment, the inlet structure and the main body and/or the outlet structure and the main body and/or the inlet structure and the first exhaust pipe and/or the outlet structure and the second exhaust pipe mate in a sliding fit.

According to an embodiment, the main body, the inlet structure, the outlet structure, the first exhaust pipe, and the second exhaust pipe are components fabricated separately.

According to an embodiment, the main body is made of metal, heat-resistant plastic or ceramic.

According to an embodiment, the main body is configured as a tube. If the tube is formed from a shaped material strip, the tube usually has a seam oriented in the longitudinal direction of the tube. The seam can be welded, soldered, crimped or glued. The pipe may also be seamless.

According to an embodiment, the main body receives an exhaust gas converter in form of a substrate. The substrate may, for instance, be a metal carrier or a ceramic carrier, with exhaust gas ducts extending through it, particularly, in a honeycomb structure. The substrate may, for instance, be a monolithic substrate. The substrate may, for instance, have two axial ends facing each other in a gas flow direction along which exhaust gas to be cleaned runs through the substrate.

According to an embodiment, the exhaust gas converter received in the main body further comprises a cushion mat arranged between the substrate and the main body. The cushion mat may, for instance, be made of wire mesh or another thermally resistant and elastic material. The cushion mat may further provide a thermal insulation between the substrate and the main body.

According to an embodiment, the inlet structure and/or outlet structure are made from a metal sheet with or without a seam, cast metal, heat-resistant plastic or ceramic.

According to an embodiment, the main body and/or the inlet structure and/or the outlet structure are provided with an anticorrosive or are entirely made from a corrosion-resistant material such as stainless steel.

In the following explanation of exemplary embodiments of the invention reference is made to the enclosed figures. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1A is a schematic view showing an exhaust gas converter body structure according to a first embodiment in one of different conditions, with walls illustrated partly transparent;

FIG. 1B is a schematic view showing an exhaust gas converter body structure according to the first embodiment in another of different conditions, with walls illustrated partly transparent;

FIG. 1C presents schematic sectional views through FIG. 1B along the section lines A-A and B-B;

FIG. 2A is a schematic view showing an exhaust gas converter body structure according to a second embodiment in one of different conditions, with walls illustrated partly transparent;

FIG. 2B is a schematic view showing an exhaust gas converter body structure according to a second embodiment in another of different conditions, with walls illustrated partly transparent;

FIG. 3 is a schematic view showing an exhaust gas converter body structure according to a third embodiment, with walls illustrated partly transparent; and

FIG. 4 is a schematic view showing a detail of an exhaust gas converter body structure according to a fourth embodiment.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, FIGS. 1A and 1B illustrate a first embodiment of an exhaust gas converter body structure 1. FIG. 1A illustrates a not yet completely assembled condition and FIG. 1B illustrates an assembled condition.

The exhaust gas converter body structure 1 has a funnel-shaped inlet structure 3, a funnel-shaped outlet structure 4 and a main body 2 located between the inlet structure 3 and the outlet structure 4. The main body 2, the inlet structure 3 and the outlet structure 4 are each made of stainless steel sheet metal with a wall thickness of 0.5 mm.

The main body 2 has a circular cross-section, a diameter of 300 mm and a length of 450 mm. For providing an exhaust gas converter, a cylindrical substrate 50 is received in the inside of the main body 2. A cushion mat 55 made of high-temperature wool substantially fills the residual gap between the substrate 50 and the inner wall of the main body 2.

A largest inner diameter of the inlet structure 3 and the outlet structure 4 is slightly larger than the outer diameter of the main body 2. This allows the main body 2 to be received by the inlet structure 3 and the outlet structure 4 in sections at first and second joint regions V1, V2. Hence, the coupling geometries of the inlet structure 3, the outlet structure 4 and the main body 2 match each other.

At each of the first and second joint regions V1, V2, the main body 2 has one bolt-shaped protrusion 23 protruding radially outwards. The coupling geometry of the main body 2 in these regions is therefore not rotation-symmetric, but rather reflection-symmetric with respect to exactly one plane of symmetry intersecting the main body 2 and the protrusions 23 centrally.

The outer walls of the inlet structure 3 and the outlet structure 4 have, at each of the first and second joint regions V1, V2, grooves 32, 42 axially facing away from the main body 2 and being open towards the main body 2. The width and length of the grooves 32, 42 are adapted to the size of the protrusions 23 such that each groove 32, 42 can receive one protrusion 23. Comparing FIGS. 1A and 1B shows that the inlet structure 3, the outlet structure 4 and the main body 2 have to be rotated such that they are oriented relative to each other in an angular position given by the positions of the grooves 32, 42 and the positions of the protrusions 23.

In addition, the main body 2 and the inlet structure 3 each have holes 25, 35 in the first joint region V1 that must align when the main body 2 and inlet structure 3a have been assembled correctly. Similarly, the main body 2 and the outlet structure 4 each have holes 25, 45 in the second joint region V2 that align when the main body 2 and outlet structure 4 have been assembled correctly. Said holes may be used for applying bolts or rivets, for example, in order to fix the main body to the inlet structure respectively outlet structure.

At their ends facing away from the main body 2, the inlet structure 3 and the outlet structure 4 are each configured for being coupled to the first and second exhaust pipes 6, 7 at third and fourth joints V3, V4. The inlet structure 3 and the outlet structure 4 and the first and second exhaust pipes 6, 7 at the third and fourth joints V3, V4 are thereby sized in pairs such that the first exhaust pipe 6 can surround a section of the inlet structure 3 and the second exhaust pipe 7 can surround a section of the outlet structure 4. In other words, the first and second exhaust pipes 6, 7 can be pushed onto the inlet structure 3 and the outlet structure 4. Consequently, the coupling geometries of the inlet structure 3, the outlet structure 4 and the first and second exhaust pipes 6, 7 match each other in pairs.

As illustrated by the sectional views of the assembled exhaust gas converter body structure 1 from FIG. 1B taken along lines A-A and B-B shown in FIG. 1C, the inlet structure 3 and the first exhaust pipe 6 on the one hand, and the outlet structure 4 and the second exhaust pipe 7 on the other hand, have different sectional areas at the third and fourth joints V3, V4 with both having no point-symmetry, but rather an axial-symmetry with respect to exactly one symmetry axis. Hence, the first exhaust pipe 6 may solely be coupled with the inlet structure 3 and in only one orientation, and the second exhaust pipe 7 may solely be coupled with the outlet structure 4 and in only one orientation.

Thus it can be guaranteed that not only the individual components of the exhaust gas converter body structure 1 are assembled in the correct angular position with respect to each other, but also that the exhaust gas converter body structure 1 is as the whole mounted on the underbody of a vehicle not shown in the correct angular position.

With the exception of the coupling geometries at the third and fourth joint regions V3, V4, the first and second exhaust pipes 6, 7 have a circular and thus point-symmetric sectional area.

Although not shown in the Figures, the coupling between the first and second exhaust pipes 6, 7 and the inlet structure 3 or outlet structure 4 may also have openings or protrusions and recesses extending inwardly or outwardly with respect the exhaust gas converter body structure 1, as well as grooves etc., as described above for the example for a coupling of the inlet structure 3, respectively outlet structure 4 with the main body 2. What matters is that the coupling geometries in the joint region are selected to enable a substantially seamless coupling of the components at only one single angular position. Accordingly, the sectional areas of the inlet structure 3, respective outlet structure 4 and the main body 2 at first and second joint regions could be chosen to be asymmetric such that a seamless coupling of the components may be achieved at only one single angular position even when protrusions and recesses as well as grooves are omitted.

In the following, a second type of exhaust gas converter body structure 1′ is described referencing FIGS. 2A and 2B. In order to avoid repetitions, primarily only differences to the above first embodiment are addressed, while for the rest, reference is made to the first embodiment. FIG. 2A shows a not yet completely assembled condition and FIG. 2B shows an assembled condition.

In the exhaust gas converter body structure 1′ according to the second embodiment, the main body 2′ has no protrusions in each of the first and second joint regions V1, V2, but a pair of grooves 22 oriented in the axial direction of the main body 2′ and open towards the inlet and outlet structures 3′, 4′ respectively. The grooves 22 in the first joint region V1 are hereby spaced apart in the circumferential direction of the main body 2′ by a first distance Al that is smaller than a second distance A2, by which the grooves 22 in the second joint region V2 are spaced apart in the circumferential direction of the main body 2′.

Instead of grooves, the inlet structure 3′ and the outlet structure 4′ accordingly have bolt-shaped protrusions 34, 44 in first and second joint regions V1, V2, which protrude into the inside of the exhaust gas converter body structure P. The distance between the bolt-shaped protrusions 34 at the inlet structure 3′ hereby corresponds to the first distance Al of the grooves 22 in the main body 2′ at the first joint region V1, while the distance between the bolt-shaped protrusions 44 at the outlet structure 4′ corresponds to the second distance A2 of the grooves 22 in the main body 2′ at the second joint region V2. Thus also here the coupling geometries of the inlet structure 3′, the outlet structure 4′ and the main body 2′ at the first and second joint regions V1, V2 match each other in pairs with none being rotation-symmetric. Therefore also here, a mounting of the inlet structure 3′ to the main body 2′ as well as of the outlet structure 4′ to the main body 2′ is only possible with an angular position defined by the position of the grooves 22 and protrusions 34, 44. The different distances A1, A2 between the grooves 22 and the protrusions 34, 44 ensure that the inlet structure 3′ and the outlet structure 4′ can only be mounted at one selected end of the main body 2′.

Although the main body at the first and second joint regions are in the first and second embodiment surrounded by the inlet structure and the outlet structure, it is alternatively also possible to configure these components such that both, the inlet structure and the outlet structure or only one of these components is surrounded by the main body in the first and second joint regions. Accordingly, the number, arrangement, and orientation of the bolt-shaped protrusions and grooves can be varied as desired.

In the embodiment shown in FIGS. 2A and 2B, the substrate 51 of an exhaust gas converter is not only received in the main body 2′, but also in the inlet structure 3′ and the outlet structure 4′, whereby cushion mats 55 surround the substrate in its circumferential direction.

In the following, a third embodiment of an exhaust gas converter body structure 1″ is described referencing FIG. 3. In order to avoid repetitions, primarily only differences to the above first embodiment are addressed, while for the rest reference is made to the first embodiment.

The third embodiment does not provide for the inlet structure 3″, the outlet structure 4″ and the main body 2″ to be slotted together. Instead, the end faces of these components abut against each other when being assembled.

Here too, the coupling geometries in the first and second joint regions V1, V2 are selected to enable a substantially seamless assembly only when the components have a given angular position relative to each other. In the illustrated embodiment, the inlet structure 3″ has for this purpose at the first joint region V1 a protrusion 31 oriented towards the main body 2″, while the main body 2″ has at the first joint region V1 a corresponding recess 22 directed away from the inlet structure 3″. At the second joint region V2, the main body 2″ has a protrusion 21 oriented towards the outlet structure 4″, while the outlet structure 4″ has a corresponding recess 42 directed away from main body 2″. The pairs of the protrusions 21, 31 and the recesses 22, 42 are hereby configured differently. Hence it is guaranteed that the inlet structure 3″ and the outlet structure 4″ can each only be mounted to one selected end of the main body 2″.

In the following, a fourth embodiment of an exhaust gas converter body structure is described referencing FIG. 4. In order to avoid repetitions, primarily only differences to the above first, second, and third embodiments are addressed while for the rest, reference is made to the first, second, and third embodiment.

FIG. 4 only intends to refer to the coupling of the first or the second exhaust pipe to the inlet structure, respectively the outlet structure. For this reason, only the first exhaust pipe 6 and the inlet structure 3* are shown as an example instead of the complete exhaust gas converter body structure.

In the fourth embodiment, the first exhaust pipe 6 and the inlet-structure 3* each have a circular sectional area at the third joint region V3. The first exhaust pipe 6 and the inlet structure 3* cannot be slotted together; rather their front faces abut against each other when being assembled. Similar to the above third embodiment, these front faces are provided with protrusions 36, 61 and recesses 37, 62, resulting in the coupling geometries not being symmetric.

Hence, a substantially seamless assembling of the first exhaust pipe 6 and the inlet structure 3* is only possible at an angular position given by the coupling geometries. A coupling of the second exhaust pipe to the outlet structure at the fourth joint region can be achieved accordingly.

Although in the above, substantially similar, and with the exception of the coupling geometries, substantially symmetric inlet structures and outlet structures have been shown, the present invention is not limited to these structures. Furthermore, an illustration of bond joints, solder joints or welded joints or crimp joints for sealing junctions that may permanently and gas-tight seal a residual gap between the components of the exhaust gas converter body structure has been omitted in the above illustrations.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

LIST OF REFERENCE DESIGNATIONS

-   1, 1′, 1″ exhaust gas converter body structure -   2; 2; 2″ main body -   21 protrusion towards the inlet structure/outlet structure -   22 recess/groove directed away from the inlet structure/outlet     structure -   23 protrusion towards the outside of the exhaust gas converter body     structure -   25 opening -   3; 3′; 3″; 3* inlet structure -   31 protrusion towards the main body -   32 recess/groove directed away from main body -   34 recess towards the inside of the exhaust gas converter body     structure -   35 opening -   36 protrusion towards the first exhaust pipe -   37 recess/groove directed away from first exhaust pipe -   4; 4′; 4″ outlet structure -   42 recess/groove directed away from main body -   44 recess towards the inside of the exhaust gas converter body     structure -   45 opening -   51 exhaust gas converter substrate -   55 cushion mat -   6 first exhaust pipe -   61 protrusion towards the inlet structure -   62 recess/groove directed away from inlet structure -   7 second exhaust pipe -   V1 first joint (between inlet structure and main body) -   V2 second joint (between outlet structure and main body) -   V3 third joint (between inlet structure and first exhaust pipe) -   V4 fourth joint (between outlet structure and second exhaust pipe) 

What is claimed is:
 1. An exhaust gas converter body structure comprising: a main body; an inlet structure; and an outlet structure, the main body being configured for receiving an exhaust gas converter, to dispose the exhaust gas converter between the inlet structure and the outlet structure, the inlet structure and the main body engaging each other at a first joint and the inlet structure and the main body have complementary first joint coupling geometries at the first joint, and the outlet structure and the main body engaging each other at a second joint and the outlet structure and the main body have complementary second joint coupling geometries at the second joint, wherein: the first joint coupling geometries of each of the inlet structure and of the main body are either asymmetric or reflection-symmetric with respect to exactly one plane of symmetry at the first joint; or the second joint coupling geometries of each of the outlet structure and of the main body are either asymmetric or reflection-symmetric with respect to exactly one plane of symmetry at the second joint; or the first joint coupling geometries of each of the inlet structure and of the main body are either asymmetric or reflection-symmetric with respect to exactly one plane of symmetry at the first joint, and the second joint coupling geometries of each of the outlet structure and of the main body are either asymmetric or reflection-symmetric with respect to exactly one plane of symmetry at the second joint.
 2. The exhaust gas converter body structure according to claim 1, wherein: the first joint coupling geometries comprise a first joint coupling geometry of the inlet structure at the first joint comprising at least one protrusion extending towards the main body or a recess extending away from the main body and/or at least one groove extending away from the main body and/or at least one protrusion extending towards an outside of the exhaust gas converter body structure or a recess extending towards the inside of the exhaust gas converter body structure and/or at least one opening; and/or the first joint coupling geometries comprise a first joint coupling geometry of the main body at the first joint comprising at least one protrusion extending towards the inlet structure or a recess extending away from the inlet structure and/or at least one groove extending away from the inlet structure and/or at least one protrusion extending towards an outside of the exhaust gas converter body structure or a recess extending towards the inside of the exhaust gas converter body structure and/or at least one opening; and/or the second joint coupling geometries comprise a second joint coupling geometry of the outlet structure at the second joint comprising at least one protrusion extending towards the main body or a recess extending away from the main body and/or at least one groove extending away from the main body and/or at least one protrusion extending towards an outside of the exhaust gas converter body structure or a recess extending towards the inside of the exhaust gas converter body structure and/or at least one opening; and/or the second joint coupling geometries comprise a second joint coupling geometry of the main body at the second joint comprising at least one protrusion extending towards the outlet structure or a recess extending away from the outlet structure and/or at least one groove extending away from the outlet structure and/or at least one protrusion extending towards an outside of the exhaust gas converter body structure or a recess extending towards the inside of the exhaust gas converter body structure and/or at least one opening.
 3. The exhaust gas converter body structure according to claim 1, wherein the first joint coupling geometries comprise a first joint coupling geometry of the inlet structure at the first joint comprising at least one protrusion extending towards an outside of the exhaust gas converter body structure and a first joint coupling geometry of the main body at the first joint comprising at least one groove extending away from the inlet structure; and/or the first joint coupling geometries comprise a first joint coupling geometry of the inlet structure at the first joint comprising at least one recess extending towards the inside of the exhaust gas converter body structure and the first joint coupling geometries comprise a first joint coupling geometry of the main body at the first joint comprising at least one groove extending away from the inlet structure; and/or the second joint coupling geometries comprise a second joint coupling geometry of the outlet structure at the second joint comprising at least one protrusion extending towards an outside of the exhaust gas converter body structure and the second joint coupling geometries comprise a second joint coupling geometry of the main body at the second joint comprising at least one groove extending away from the outlet structure; and/or the second joint coupling geometries comprise a second joint coupling geometry of the outlet structure at the second joint comprising at least one recess extending towards the inside of the exhaust gas converter body structure and the second joint coupling geometries comprise a second joint coupling geometry of the main body at the second joint comprising at least one groove extending away from the outlet structure; and/or the first joint coupling geometries comprise a first joint coupling geometry of the inlet structure at the first joint comprising at least one groove extending away from the main body and the first joint coupling geometries comprise a first joint coupling geometry of the main body at the first joint comprising at least one protrusion extending towards an outside of the exhaust gas converter body structure; and/or the second joint coupling geometries comprise a second joint coupling geometry of the outlet structure at the second joint comprising at least one groove extending away from the main body and the second joint coupling geometries comprise a second joint coupling geometry of the main body at the second joint comprising at least one protrusion extending towards an outside of the exhaust gas converter body structure.
 4. The exhaust gas converter body structure according to claim 1, wherein the main body is reflection-symmetric or rotation-symmetric except for a main body first joint coupling geometry associated with the first joint coupling geometries and a main body second joint coupling geometry associated with the second joint coupling geometries; and/or the inlet structure is rotationally symmetrical apart from an inlet structure first joint coupling geometry associated with the first joint coupling geometries; and/or the outlet structure is rotationally symmetrical apart from an outlet structure second joint coupling geometry associated with the second joint coupling geometries.
 5. The exhaust gas converter body structure according to claim 4, wherein: the main body has, at a distance from the main body first joint coupling geometry, a point-symmetric or axis-symmetric or circular sectional area or oval sectional area; and/or the main body has, at a distance from the main body second joint coupling geometry, a point-symmetric or axis-symmetric or circular sectional area or oval sectional area; and/or the inlet structure has, at a distance from the inlet structure first joint coupling geometry, an asymmetric sectional area; and/or the outlet structure has, at a distance from outlet structure second joint coupling geometry, an asymmetric sectional area.
 6. The exhaust gas converter body structure according to claim 1, further comprising: a first exhaust pipe that engages the inlet structure at a third joint, the inlet structure and the first exhaust pipe having complementary third joint coupling geometries at the third joint, wherein the third joint coupling geometries of the inlet structure and the first exhaust pipe are either asymmetric or reflection-symmetric with respect to exactly one axis of symmetry; and/or a second exhaust pipe that engages the outlet structure at a fourth joint, the outlet structure and the second exhaust pipe having complementary fourth joint coupling geometries at the fourth joint, wherein the fourth joint coupling geometries of the outlet structure and the second exhaust pipe are at either asymmetric or reflection-symmetric with respect to exactly one axis of symmetry.
 7. An exhaust gas converter body structure comprising: a main body; an inlet structure; an outlet structure, the main body being coupled to the inlet structure and being coupled to the outlet structure and the main body being configured for receiving an exhaust gas converter with the exhaust gas converter disposed between the inlet structure and the outlet structure; a first exhaust pipe engaged with the inlet structure at a pipe and inlet joint, the inlet structure and the first exhaust pipe having a complementary pipe and inlet joint coupling geometries at the pipe and inlet joint, the pipe and inlet joint coupling geometries being either asymmetric or reflection-symmetric with respect to exactly one axis of symmetry; and/or a second exhaust pipe engaged with the outlet structure at a pipe and outlet joint, the outlet structure and the second exhaust pipe having a complementary pipe and outlet joint coupling geometries, the pipe and outlet joint coupling geometries of the outlet structure and the second exhaust pipe being either asymmetric or reflection-symmetric with respect to exactly one axis of symmetry.
 8. The exhaust gas converter body structure according to claim 6, wherein: the pipe and inlet joint coupling geometries comprise a pipe and inlet joint coupling geometry of the inlet structure at the pipe and inlet joint comprising at least one protrusion extending towards the first exhaust pipe or a recess extending away from the first exhaust pipe and/or at least one groove extending away from the first exhaust pipe and/or at least one protrusion extending towards an outside of the exhaust gas converter body structure or a recess extending towards an inside of the exhaust gas converter body structure and/or at least one opening; and/or the pipe and inlet joint coupling geometries comprise a pipe and inlet joint coupling geometry of the first exhaust pipe at the pipe and inlet joint, comprising at least one protrusion extending towards the inlet structure or a recess extending away from the inlet structure and/or at least one groove extending away from the inlet structure and/or at least one protrusion extending towards an outside of the exhaust gas converter body structure or a recess extending towards the inside of the exhaust gas converter body structure and/or at least one opening; and/or the pipe and outlet joint coupling geometries comprise a pipe and outlet joint coupling geometry of the outlet structure at the pipe and outlet joint, comprising at least one protrusion extending towards the second exhaust pipe or a recess extending away from the second exhaust pipe and/or at least one groove extending away from the second exhaust pipe and/or at least one protrusion extending towards an outside of the exhaust gas converter body structure or a recess extending towards the inside of the exhaust gas converter body structure and/or at least one opening; and/or the pipe and outlet joint coupling geometries comprise a pipe and outlet joint coupling geometry of the second exhaust pipe at the pipe and outlet joint comprising at least one protrusion extending towards the outlet structure or a recess extending away from the outlet structure and/or at least one groove extending away from the outlet structure and/or at least one protrusion extending towards an outside of the exhaust gas converter body structure or a recess extending towards the inside of the exhaust gas converter body structure and/or at least one opening.
 9. The exhaust gas converter body structure according to claim 7, wherein the pipe and inlet joint coupling geometries comprise a pipe and inlet joint coupling geometry of the inlet structure at the pipe and inlet joint, comprising at least one protrusion extending towards an outside of the exhaust gas converter body structure and a pipe and inlet joint coupling geometry of the first exhaust pipe at the a pipe and inlet joint, comprising at least one groove extending away from the inlet structure; and/or the pipe and inlet joint coupling geometries comprise a pipe and inlet joint coupling geometry of the inlet structure at the pipe and inlet joint, comprising at least one recess extending towards the inside of the exhaust gas converter body structure and a pipe and inlet joint coupling geometry of the first exhaust pipe at the pipe and inlet joint, comprising at least one groove extending away from the inlet structure; and/or the pipe and outlet joint coupling geometries comprise a pipe and outlet joint coupling geometry of the outlet structure at the pipe and outlet joint, comprising at least one protrusion extending towards an outside of the exhaust gas converter body structure and pipe and outlet joint coupling geometry of the second exhaust pipe at the pipe and outlet joint comprising at least one groove extending away from the outlet structure; and/or the pipe and outlet joint coupling geometries comprise a pipe and outlet joint coupling geometry of the outlet structure at the pipe and outlet joint, comprising at least one recess extending towards the inside of the exhaust gas converter body structure and a pipe and outlet joint coupling geometry of the second exhaust pipe at the pipe and outlet joint comprising at least one groove extending away from the outlet structure; and/or the pipe and inlet joint coupling geometries comprise a pipe and inlet joint coupling geometry of the inlet structure at the pipe and inlet joint, comprising at least one groove extending away from the first exhaust pipe and a pipe and inlet joint coupling geometry of the first exhaust pipe at the pipe and inlet joint, comprising at least one protrusion extending towards an outside of the exhaust gas converter body structure; and/or the pipe and outlet joint coupling geometries comprise a pipe and outlet joint coupling geometry of the outlet structure at the pipe and outlet joint, comprising at least one groove extending away from the second exhaust pipe and a pipe and outlet joint coupling geometry of the second exhaust pipe at the pipe and outlet joint, comprising at least one protrusion extending towards an outside of the exhaust gas converter body structure.
 10. The exhaust gas converter body structure according to claim 7, the pipe and inlet joint coupling geometries comprise a pipe and inlet joint coupling geometry of the first exhaust pipe at the pipe and inlet joint and the first exhaust pipe is either reflection-symmetric or rotation-symmetric apart from the inlet joint coupling geometry of the first exhaust pipe at the pipe and inlet joint; and/or the pipe and inlet joint coupling geometries comprise a pipe and outlet joint coupling geometry of the second exhaust pipe at the pipe and outlet joint and the second exhaust pipe is either reflection-symmetric or rotation-symmetric apart from the outlet joint coupling geometry of the second exhaust pipe at the pipe and outlet joint. 